Process of selectively chloridizing manganese in the treatment of materials containing iron and manganese



Patented Nov. 10, 1953 PROCESS OF 'SELECTIVELY CHLORIDIZING MANGANESE INTHE TREATMENT OF MA- TERIALS CONTAINING IRON AND MAN- GANESE Irving P.Whitehouse, South Euclid, and Marion Ernest Graham, Parma, Ohio,assignors,1 by mesne assignments, to Republic Steel Corporation,Cleveland, Ohio, a corporation of New Jersey No Drawing. ApplicationOctober 5, 1951, Serial No. 250,032

7 Claims. 1

The present invention relates to a process of selectively chloridizingmanganese in the treatment of materials containing iron and manganese.More particularly, the present invention relates to the treatment ofmaterials, such as ores or semi-processed materials, which con,- tain apreponderance of iron, usually in oxide form, and a relatively smallamount of manganese, which may also be in oxide form, for the selectivechloridizing of this material to produce a mixture of manganous chloride(MnClz) and ferrous chloride (FeClz), wherein the proportion ofmanganous chloride to ferrous chloride is at least about 1:1 andpreferably about 4:1- or greater.

It has been known for some time that iron oxides, whether the iron be inthe form of FeO, F6203 or F6304, may be reacted with hydrogen chloride(HCl) to form ferrous chloride. It is also known that manganesecompounds, such as manganese oxides, may react with HCl to formmanganous chloride (M11012). The prior art teaching generally is thatthe tendency of these two metallic oxides to be converted by reactionwith HCl to the corresponding divalent chlorides is approximately equal.It is also known that if either iron or manganese is present in amaterial, alone or mixed together, they may be reduced from a highervalence form to a valence of two respectively by reduction withhydrogen. The combined reduction from a higher valence form to a valenceof two and the conversion of the divalent metal to the chloride byreaction with I-ICl is known as to each of these metals individually. Asfar as is taught in the prior art, the tendency of the combinedreduction and chloridizing reactions, as to each of these metalsindividually, is about equal. Based upon these known facts, it wouldreasonably be assumed by those skilled in the art, that if a materialcontaining both these metals, in most or any of the forms in which thesemetals occur in nature, were exposed to a gas containing both hydrogenand HCl, the metals would be appr ximately equally converted to therespective hlorides. Thus, it would reasonably be expected that if anore were treated in this way, and if the ore contained substantiallymore iron than manganese, as-in the case of most naturally occurringores of these two metals, the resulting chloride mixture, to the extentthat it was formed, would contain the two metals in approximately thesame proportion as that in which the metals were present in the originalore. This normally expected result is based upon known activities ofthese two metals as aforesaid, both from the chemical and thethermodynamic points I of view.

The present invention, however, is based upon an unexpected discovery,in that it is found that when a material, such as an ore orsemi-processed material resulting from an ore, containing both iron andmanganese, wherein theamount of iron present'is substantially greaterthan the manganese present, is treated with a mixture of HCl andhydrogen, with or'without-other gases which are relatively inert insofaras the present process is concerned, the manganese is converted tomanganous chloride to a far greater extent, at least at the firstportionof the reaction, than the conversion of the iron to ferrous chloride.Thus, if such a solid material, as a natural ore, is maintained in areaction zone at a temperature in a desired range, which has been foundto be from about 300 F. to about 900 F.,

and more particularly and preferably from about j 400 F. to about 800F., and if the gas concentrations in the reaction zone are withincertain desired limits as hereinafter set forth, the manganese will beconverted to manganous chloride before too large a proportion of theiron is converted to ferrous chloride. This discovery may then be taken'advantage of by stopping the process at the proper point to produce asoluble material, as a mixture of the chlorides of these two metals,which may be further treated in any desired way,'some of which will bementioned hereinafter, to produce a valuable mixture or;

The present process may be summarized, there- I fore, as one in which asolid material'of the' type hereinabove described is treated in a re-vaction zone with a gas containing hydrogen and HCl, and at a temperaturein the desired range as aforesaid, for a period terminating at asuitable time, so that the final product will contain atleast 50% of themanganese initially present in the form of mangenese chloride (MnClz)and a relatively small proportion of the iron, not more than the amountof manganese as an outsidelimit, and preferably substantially less. Thisamount of manganese may be considered in respect to the iron either on amol basis or on a weight basis, as both are substantially the same) 3due to the similarity of the atomic weights of the iron and..manganese.If the process were carried on-under' substantially the same conditionsas herein contemplated, but for a too long time, it is recognized thatmore iron would.

be converted to ferrous chloride, so that the selectivity according tothe present invention,

would be effectively absent. Thusthe-presentinvention specificallycontemplates terminating the operation of the process at a time when thechloridized material has a desired composition,

This will be set forth in greater-detail1hereinafter.

Turning now to the details of the-present-process, the first thing toconsider is the composition and character of the raw materialgwhich maybe treated according to the present process to p,ro-.

duce results desired in accordance therewith. This material includesmany naturally occurring ores as such. Among such ores which arecontemplated for use in accordance with the present invention" are 7 (1)Georgia Ochre ore which is found, as' thename" implies; iii-variousparts of the state of Georgia; having atypical analysis as follows Percent Tota1 E'e 42.40 Ignitionloss 12.94 sii. 10.87 4.70

f 0.32 M' ol p 2 Ba' 5Qr;, .50

(2) Red Aroostookmre which-is found in Aroostook County, in the-State ofMaine, and having atypical analysis as-follows Per cent TOta1 F'eIgnition losse 9.51 SiOz- 15.38 Mn-- 12.09 CaO 4.47.

(3) Blue A'roostook ore, also .found in A'roostook. CountyQin. theStateofMaine, havinga typical analysis as follows:

Per cent Total Fe I 2853.. Ignition. lcss 7.94.. S102, 14.39 Mn 8.41.cao. f 3.65

1t is also ccntemplated that variousconcene trate .-.or--'semiprmessed-materials, including materialsmade from the -ores---aforesaid,- may be similarly treated by the process or I the presentinvention. It is iurther-contemplated that materialsresulting from otherprocesses-and-Which of. theepresent. invention;

n -con emnla edii n se srr w mat r alsrin. ace

no tdence.w ththispmcessi. flow rer, practically).

4 all iron-manganese ores include a substantial preponderance ofironin..respect to, manganese andare, therefore, to be consideredas;suitable raw materials on which the present process may be practiced.

The next factor to be considered is the particle: sizesrequired :for thesolid material aforesaid, for treatment accord-ing to the presentprocess. Inasmuch as-this is a gas-to-solid type reaction, relativelysmall particle size is usually desired.- This willatend to increase thegas-to-solid contact-and, therefore, will be desirable according tothe-.presentiprocess. On the other hand, relativelylarge particle size,such as 8-mesh or larger, will introduce substantial difiiculty, if notthe.,comp lete, impossibility, of contact between the gas and thematerial in the center of each largeparticle. As such, therefore, in theevent that the original material to be treated is in relatively largeparticle size, it is desirable that it -be suitably comminutedin: anydesirediman ner, to bring .the particle sizedown tofia' point: such thatreasonably complete gasto-solid con tact is .available. Some .of thenaturallyoccur- I, ring ores, such .as Georgia: Ochre, are normally:inth'e form-of fine-particles. With-this type ofore, little or nocomminution is necessary. On the other hand-,- other'types -.oi oressuch astedor .blueAroostookrore are in the form-of rela-tively large.hard lum-ps which should-' firstbe' com minutedbefore continuing with:the steps of the presentprocess, per set It isusuallylpreferredthattheore be of vaparticle si-zecf 50-=mesh::and--finer and preferably 100.mesh and finer-4- On the other hand, particlesize is not absolutely critical ash; is: essential. onlyto obtain good:gas-to-solid contact during the reaction:-

The. next .factor. to: s be considered is the type of apparatus. inwhich .the process is tobe carried on.. Inasmuch. as :the.processeinvolves a, gas-to solid. contacta reaction atLatemperature-whichis s elevated .in respect to room temperature; any:apparatus providingtheseconditions may b'esuit able forusez. As manytypesof apparatusiare now: known WhEIGlI1;Sl1Gh..- conditions .may: be:main tamed, .no. one. apparatus. :iswparticularly critical-I and; noneis iilustrated in" connection: with: the present; application;Thesessential characteris-- tics requiredior; the apparatus 1.tobe-used, are: those which, shouldfprovide good gastoesolid -'con- Wtact, and which .should; :provide: for-the -ma-intee nance-of. thedesired: temperatures for-the reac tion. In. generaL. continuous typesof apparatus are preferred :in respect to intermittent cr batchi types,as thecontinuous types offer greater pro dllCtiOn'JiIli a given time. Itisporitemplateda for example, that suitable fluidizednbedstype apparatus ;is desirable for .use; as :this type of appa ratus,..which'-isfnow well known in the-art oifers a-maximum. .gas-to.+solid.contact, whilepermit ting adequate; temperature: control. It is also"contemplated that suitablerotary kiln-type apparatus: may: bemsed; andit is' =noted in-'-this connection .thattthis. type: oi: apparatus 1 was-in-fact used in .connectionsvwithemany of the examples of this.aprocess hereinafter" set -fortl11-= In such apparatus a good gas-tosolid' contact isafforded accompanied, by: a: substantialdegree ofagitation, so: that :the gas can reach and react w-ith stantially. all ithe particles-of 1 the solid Ina-- terial: Other. types ofgas-to-solidcontac-t ap paratus, as=.will occur tothose-skilledintheart;preferably accompaniedlby ,agitation: means;- are also tobe;considered:asfeasi-ble and operable in ying out rtherpresentsprocess. For bhe puri 5. poses of the present application, any and allsuch apparatus is generally included in the term reaction zone intowhich this solid material is introduced and/or through which it ispassed for the purposes of the present process.

The next factor to be considered is temperature. It has been found thatthe present process may be carried on advantageously in a temperaturerange having as its extreme limits from about 300 F. to about 900 F. Itis noted that these temperature limits are both relatively low inrespect to the temperature limits normally contemplated for thechloridizing of iron oxide-containing material with HCl where manganeseis either absent or wherein the selective chloridizing of the manganesein respect to the iron is not particularly desired.

The reasons for choosing the present limits are that at temperatures aslow as about 300 F., the hydrogen present in the gases as generally setforth hereinabove, does not seem to be particularly reactive to reducethe iron and manganese from a higher valence to a valence of two. Thus,for example, some of the iron may be chloridized to form ferric chloride(FeCls) and the hydrogen present be relatively inactive to reduce thisFeCls to FeClz. Inasmuch as the present process is intended to makeferrous chloride, to the extent that any iron is chloridized, asdistinguished from ferric chloride, the temperature of 300 F. isselected as the effective and practical low temperature limit of theprocess.

The high temperature limit of 900 F. is chosen by reason of the desiredselectivity of the reaction becoming progressively less as thetemperature rises. Thus, at temperatures at or above about 900 F., theiron tends to chloridize almost as fast, if not faster, than themanganese. As such, at temperatures above about 900 F., selectivity,which is the principal feature of the present invention, is effectivelyabsent. For this reason, therefore, about 900 F. is considered as thetop limit for temperature in accordance with the present invention, andto attain the desired results thereof.

While the extreme limits have been chosen for the reasons aforesaid, apreferred range of temperature from about 400 F. to about 800 F. is setforth herein, these preferred limits being chosen based upon the sameprinciples as set forth above as to the outside limits respectively, butwith a purpose of keeping furtheraway from the difiiculties which causethe outside limits to be selected as aforesaid. Within this narrowerpreferred range, the desired results according to the present invention,are more certainly attained.

Another aspect of temperature is its general efiect upon the rate ofreaction. The present reaction, as in the case of many other chemicalreactions, occurs more rapidly at higher temperatures. Thus, if it isdesired to employ only a relatively short time of contact between thegas and the solid material, operations in the higher end or portion ofthe temperature range aforesaid are usually preferred. On the otherhand,

it must be kept in mind that the carryingon of the reaction isprogressively more expensive as higher temperatures are used, due to thegreater amount of heat required and the loss of such heat as sensibleheat of the solid material at the completion of the reaction. Thedesired temperature may, therefore, be chosen finally based upon aneconomic balance between the speed of the reaction in the highertemperature ranges and the increased cost of maintaining the processwhile operating in such higher temperature ranges.

The next factor to be considered isthe gas composition. In general, thegas must contain both hydrogen and H01. The requirements and effects ofthese two gases will now be separately considered.

As both the iron and the manganese may be in a valence state greaterthan a valence of two in the original material supplied to the process,

some reduction of one or both these metals to a valence of two isusually necessary. Also, in the event that either of these metals wereconverted to a chloride having a valence greater than two, it is desiredto convert such chloride to a divalent state and to reconstitute theremaining chlorine as HCl for the continuance of the reaction withunchloridized solid material. Thus, it is essential that some reducingagent, as hydrogen, be present. On the otherhand, inasmuch as reductionis the only need for hydrogen, there need only be enough hydrogen toassure that ther is always some hydrogen available to effect suchreduction as may be required. In order to assure this, it is found thatif the gases leaving the reaction zone contain at least some hydrogen,or in other words, contain at least a trace of hydrogen, then there isan assurance that there has been enough hydrogen to do everything thathydrogen can properly do. For this reason, therefore, the concentrationof hydrogen in the incoming gases is not particularly important, but thepresence of some hydrogen in the outgoing gases seems to be essential toassure the presence of hydrogen throughout the reaction. Excess ofhydrogen does not appear to be at all harmful, as such excess hydrogenacts merely as an inert gas, insofar as the desired reaction isconcerned.

As to the upper limit of hydrogen, it may be considered that there isalways a possibility that hydrogen might react either with one or moreof the oxides of iron, to reduce the iron from the oxide form to ametallic state or to reduce ferrous chloride to metallic iron. It isfound, however, that either of these reactions will take place quiteslowly until the uppermost range of temperature, in accordance with thepresent invention, is reached; and further, that the presence in'thegases of some HCl will tend additionally to depress the rate ofreduction of iron to the metallic state, irrespective of the ironcompound which is to be reduced. On the other hand, it is practicallyimpossible, in the temperature range according to the present invention,to reduce manganese to the elemental or metallic state with hydrogen, sothat this possibility need not be seriously considered. As a practicalmatter, the presence of HCl in the concentrations normally used asherein set forth, will preclude all but a substantially negligiblereduction of the iron to the metallic state except, perhaps in thetemperature range above 800 F., and even at these temperatures, the rateof reduction of the iron is relatively slow in the presence ofsubstantial amounts of HCl and is also retarded by water vapor. Thispossibility may, therefore, be effectively disregarded when operatingaccording to the preferred range embodiment of the present process, evenwith the maximum amount of hydrogen permissible by differences betweenthe amount of HCl present as hereinafter set forth and The onlyefiective limit, therefore, upon the hydrogen concentration is thatthere should be sufficient hydrogen, so that the exit gases will containat least a trace of hydrogen.

73 Examshse i: eehyd eene qn ntrat oii:i s hea gases as actually used inthe practice of the proo sa w za pe r nvt e am e hich .io p

The .;-otherl essential; ingredient in the gases which are passedthrough the reaction zone, is HGL; This gas, (H01) :is-requiredfioconvert mall-I, ganese and iron, which has been brought to -a valence oftwo by the hydrogen, to, MnClz and F8012 respectively. view.,-of the--fa, ct that the; purposeof -,theprocess .is primarily to convert the,manganese present to MnQlz, ,,there. should be sufficient HCl presentto-rlo,this. Thus while the total amount otHCl to which the solid material is exposed. .while it i is in the, reaction :zone is hot-exactlycritical, it is usual and islpreferred to, su ply at least enough HClinto contact with, theisolid material, during. the total period ct con stact between the: solid material; and the;gases-,-, to. convert all themanganese-present .in the-solid material to MnClz Thus: while theUHClcon centration in the gases may beivariedin differ; l ent tests or indifferent operations, during which, the .process is practiced, theremustalways be sufilcientHClto convert the,- amonnt of,-ma n-. ganese toMnClz, Whichitis-desired to so;.con-.. vert,. and preferably also.enough to. convert .all. the manganese present to MIlClz. On the other;hand, itisinotdesired to convertiron to Feclz, except to the extentthatsuch conversionissun avoidable and ,isdncidental i to. v the desired,con-. U

version of manganeseas aforesaid For this rea-, son,- theiron.contentotthe, original raw material is not considered determining how.much .HCl is to b'e used. Normally, it is, quite usual to, usemorehthan enough HCl ins-respect .to thBStDiChiOr metric, amountrequired to convert all the. man-.- anese ,present ,towMnClahforexample, one and one-half times as, much as thisstoichiometric amount.Under most circumstanceahowever, this ratiois probably to be consideredas a high, limit; as it isnsuallyundesirable to use substan1-tiallYmoreHCl than is necessary, assuch excess H01 tends to increase the.chloridization ,of the. 1 10 1 Th us far, the discussion h' asappliedjo the, totaljiam unt HQ1;in. .th eas sin contact with y\particular por i n f the solid material ,durins. the a pa s e f; suchportion throu h h reaction, zone, or while, such rportion is in thereaction zone, asin the case of a batchtyper op erationfas to thesolidtype material; The' q htrationh i CLi e as i Q-t par.- ticularlycritical.,, The. essential feature isithatr durin the timeany portion ofthe. solid m a teriali in contact Withfihfi gases, suffieientI-LC};willbe brought into contactstherewithfltofiefer feet desir,edresul,ts.,This can beaecomplishedi therefore, by, using a lower concentration andat longer time, However, in view oijthe fact that." time. is in mostinstances directly related .to the. economy-f the process, it is usuarto supply n HCl concentration such that the process maybe, completedgtothe extent desired in anreasonable times Thus, Whilethe concentration,of HCLin hesases is. not acritical factor, it is usu l 130 use at least6%1-101 by volume in the gases,.and, preferably somewhat more, asillustratedbythei examples, which ,follow.

Thergasespassed throu h. the reactio zone as: aforesaidmay also containmoraor. lessdnert gas, by, which is meant gases which are-inert. insofaras the present reaction is concerned, as; well as those gases which aregenerally accepted as. inert per, se, such as, nitrogen. It is, desired,of, coursef that there be nothing; in, the-- gases 8: hemselr st eh li;n, er-ie af iths hea e itei-z s r om w ,sto s s he. o e.-,., ee i rtionai ases;w ch-, r -ma not r sents, other than'the essential gasessuch ashydt-Ofien and HCl, may beofsany desirednatureandmay be epresentin any .desired; amount ofv concentration,- as long -as they donotinterfere suliystan lv tiallymith the; operation of the ,process ,as,here l inset; forth; Examples of gaseous-mixtures in luq issmo less n ta es e tilfi h e e aiter.-..

Th i-nexti si nt 1- nsicl ed sh aths-2% tionof the-operation of theprocess, that s; thee time of; exposure-oi; the. solid; material in threa t on; ne; os a ee eo s.-. x ur ra s a; her t cueha la; h ipe t e;in; 1111 zone is suitably controlled and maintained as ajoresaid Theprocessshould-be carried- 0 a time periodjsufficient to convert ;.adesireii gaxyi 20 bstantia a ount ft-t zman enes s sese i tee manganouschloride (MnC,l2);. Foiythe purpgsesy, obthe presentE application, thistime period is selected as- -that in which at; least Q-% 0L thmanganese; present may; be thus-l-convertedor Ql di d-=' Norma y; yi dsu stant ally: r ate t an: 5 i. .the; m n anes int e or of manganouschloride are desired; and; re fact attained-,as -.il-lus trat edby manyoii th, e ampleswhich follow; On the 0thelhandp theQ pr e so l not eo ned; o i u hi a one: periodthat iron is converted-to the form ot fer rouschloride -to an undesired e rten In-, OthQi Words, it; is essentialthatv the-i process be; npt continued too-long; This be determinedpractically and, wi-th v avery; -fe experiments ;by; the, composition:oi the: resulting; solid matergi d y; also. e et rmihe i o i anperatippoint of View by theecompositionno f e: ea e mpar da i hehompeei ionLOI. he: e asesbeina pl ed a t he: ac ion;- e eiu hes t pl i-such sshsiher nowhwrime: determined, For example, ii -may be desired te make aproduct whiclr willcontain abo, 8 M1 1 n e-Gl cons dering-,1 n y; he:chloridized material). Under such; ci ances h e mpu iti iimrri e net h.l

ized, tends;to exceed, about one, a part 1 for; every; our ar s-h man ae h eii-i ze s t siseec erally about vtime to stop the; process; a a,con: tinuance-of i the process follow-i-ng this tir-ne :w ll; u -tinmuci-iimose on bein hlorid r d; manganese Examples or ;the amounts andprp s portionssof' iron and manganese; chloridiaed will; e i n, r it i;lus t n -1 wthe time; for =cessation oi i the process inay bereadily de:4 m -ned 'e fi thos i e in the art .for h r ive iz set of conditions.While no absolute theory can; begivemwhjeh will-explain in detail or infu-l -l zthe desired;re SUltS-sWhiCl-l areFinfaet attained-byi-the preseta: process, itis believed-that when startinggwith mat rial inc d ng a.mflonnmtiom t: 39111: someoxide form, and a-relatively; non; portion; fma an s ome or m xamp e, ha xide. formh r h s; which: appen are: thesimultaneou reduction-oi the-two metals tqg a divalentstateand then the-conversion 5O5S01I3 of the, iron to a; chloride forrra Following:this;; itrisbelieved that-an interchange;reaction;o curs between-ferrouschloride and Mn 1va FeQ plus -MnCl2l; Theextent to;which-;th is ing,terehang ereaction oecurs; as; contrasted; with; the rateat whichmanganese pxida-ischloridized; y direct t on {with theeases s hotnown;HQWQV t is; lieved thatdhe surprising res--- 'sults of the presentprocess in the selective chloridizing of the manganese as compared withZ Once the process proper has been completed in accordance with thepresent invention, it is desired usually to separate the chloridizedmanganese and iron from the remaining material. This can be effected bya leaching operation, due to the soluble character of the chlorides ascontrasted with the insoluble character of the remainder of the originalmaterial, thus, the solid material resulting from the process, after ithas been removed from the reaction zone and cooled to room temperature,may be leached with water ing to the present invention. However, even into dissolve out the soluble chlorides, then the solution separated, asby filtration or decantation, from the insoluble material, and thesoluble material recovered from the solution by evaporation.

' Another way in which the manganese and iron chlorides may be removedfrom the remaining .2

material is by vaporization that is, by heating the solid material up toa point where MnClz and FeClz will both vaporize. By condensing-theresultant vapor, the chlorides may be recovered.

By the use of a suitable gas, such as nitrogen or any other relativelyinert gas, the temperature of vaporization of these chlorides may bebrought down somewhat below the normal boiling points of these twochlorides as will be obvious to those skilled in the art.

Irrespective of the way the chlorides are separated from theremaining-material as aforesaid, the metals may be recovered from thechlorides in any suitable way, forming per se no part of the presentinvention and which, therefore, are

not specifically disclosed herein.

As illustrative of the practical operation of the process, the followingexamples may be given:

Example I This example is given to illustrate the selective character ofthe present process asapplied to different types of raw materials. Forthe purpose of this example, three different types of naturallyoccurring ores were used. In each test hereinafter given in thisexample, 150 gramsamples of the ore was supplied to a rotary furnacethree inches in inside diameter and five inches long. A gas composed ofhydrogen and 20% HCl Was passed through this furnace for one hour, therate of gas flow being such that during this time period, one andone-half times the stoichiometric amount of HCl was passed through thefurnace, calculated in respect to the amount of H01 required to convertall the manganese present in the ore to MnClz. In each test the materialin the furnace was maintained at about 600 F. In the first testhereinafter given a relatively easily chloridizable ore was used, sothat the results stated show an adequate amount of chloridizing inaccordance with the present invention; while in the other testsrelatively difiicultly chloridizable types of ores were used, so thatthe time period permitted was inadequate to effect the desired amount ofchloridizing, accordthe later tests, the selective character of thechloridizing is apparent.

A. Using Georgia Ochre ore of the composition given above and under theconditions stated, it was found that the resulting solid materialcontained 3.31% soluble manganese (as MnClz) 0.95% insoluble manganese,1.75% soluble iron (as FeClz) and 43.2% insoluble iron. Thus 77.5% ofthe manganese was converted by the reaction to MnClz, while only 3.9% ofthe iron was converted to FeClz. In the soluble product, there was aratio of manganese to iron of 1.9:1.

B. In this test Red Aroostook ore of the composition given above wasused. Upon analysis of the solid product of the reaction, there wasfound 3.9% soluble manganese, 8.7% insoluble manganese, 0.4% solubleiron and 29.7% insoluble iron. Thus 31% of the manganese was convertedto MnCh; while only 1.3 of the iron was converted to FeClz. The ratio ofthe manganese to iron in the soluble final product was very high in thiscase, although this ratio 'is not considered as conclusive, as theprocess was not carried on for a sufiicient time for this type of rawmaterial during this test. The selectivity, however, of the chloridizingis unquestionable.

C. In this test Blue Aroostook ore of the composition given above wasused, giving a resulting solid material containing 2.87% solublemanganese, 6.91% insoluble manganese, less than 0.1% soluble iron, and30.1 insoluble iron. Thus, the manganese was 25.5% converted to MnClz,while less than 0.3% of the iron was converted to Feclz. Again the testwas carried on for too short a period of time to give proper resultsfrom the point of view of the present invention or to determine theeventual ratio of manganese to iron which would have been attained hadthe process been carried on for a time period adequate for treating thistype of ore.

Example II The purpose of this example is to illustrate the effect ofvarying temperatures on the reaction.

I In all tests in this example Red Aroostook ore of the compositiongiven above was used.

A. In the first test illustrating the operation of the process at a verylow temperature, a 3.5 gram sample of the ore in a finely groundcondition (all through 325 mesh) was exposed in a still bed to a gascontaining, per minute of gas flow through the reaction chamber, cc.HCl, 15 cc. H2 and 1520 cc. N2. The temperature of the reaction chamberwas maintained at about 300 F., and using a 360 minute test time period,the resulting product upon analysis, showed that 48.0% of the manganesepresent had been chloridized to MnClz, 2.8% of the iron had beenchloridized to FeClz, 7.8% of the iron had" been chlorized to FeCla. Theratio of manganese to iron in the soluble portions of the solid productwas 1.66:1. This test is considered to show that at this low temperaturethe reaction is quite selective, but due to the low temperature and tothe presence of only a very small amount of hydrogen, a considerableamount of the iron was chloridized to ferric chloride, rather thanferrous chloride.

In a further test with conditions otherwise the same but with thetemperature held at about 400 F. for 180 minutes, it was found that72.5% ofthe manganese was chloridiz'ed to MnClz and 6.3% of the iron waschloridized to FeClz; In this test there was no FeCla found in the finalpro'duct. "Thus this testgave afi-solubie":product having a ratim(ifmanganese to' iron' ofi4f47iz 1.

B. This test was carried-:on -at a higherfltemperature' within thepreferred;:rangegini 'thisiease 1 :conneotion rwith Example' I,andeusing? 150 anesh ore "(Red Aroostook .Of i the r compositioniigiven:aabove). 'ilThe gas rates zinfithis test'ztper minute) were .510ices-Hz: and 50 :cc. The zgasiwas -.spassedrthrough theifurnaceiforastotal time-f tuIBZL-minutes, cduring zwhichztimei 110%401? zitheilStCiChiOmEtiiC amount of'I-ICI 1(torconvertrall; the

a manganese present tolMnClz) :passed throughthe iiurnace.

ilimaifirstxte'st under theserconditions carriedron :zatw'GOO"; E; 55.9r; of :thetmanganese was chlorridizechtdzMnClaarid 82% :of-theiron'zwaszehloirridized': :torFeClae giving a:solubleztprodu'ctzmavring-;.a ratiopofmanganese to- -iromoi2.66: 1.

Inca; second: testz under theses conditionsnbut awitlrtheztemperatureat8.00??1i.-; itzwas found that (F-79.4% :of the manganese was:iohlo'ridized mto jsMnClz; :while 811%.: of: the: iromwasmhloridizedvtocFefllaz-zgivingaaw manganesewto: :iron ratio inwzthe'rawaten-solubleiproduetqof-3.823 1.

C. A=iurthertestrwas=carried on=;at.the "extreme high limit oftemperatur e;:900.-:F.; inva'ocordance ewith; the.'present;. invention;ithis test? being under -,-the ssa'merstillnbedaconditions .zdescribedwin: re-

.; spect; toi-ExamplezII ,(--A) sand using-1a: 6:9 gram .esamplesofi thesameReduAroostook ore; the':com-

,vposition Of 'WhiChJi-Sfi; given above. SThiSifSaZmPIB :"was ground wto ea-lla-m'inus 2-100 :mesh. The @test :was' r-unsforiza periodeof.5240-: minutes yusing lcn 1 cc.-of HCtand ilaccsofeHz, both perminute..The sresultingz-amaterial ;contained:-89=4% of thex-Mn =;.-present--:as-.Mn1a-:and:.-58;6 %-:of ;;the FFe: present was FeC12, givir :aratioaohmanganese-to ironfin ithe soluble. productof;-0;61; 1.:This'ttest isg'given to .show. that. :w-hen .the: temperatures. is:raisedzzup to this high point, the tendeney -foriironto chloridize is sogreat in respect to the chloridization of the iron at lowertemperatures, that the selectivitytends to go outsidehtherdesired range.:Thus a. temperature.of .about 900. Fmmay.- be considered as About L theuppermost temperature .lilimit rat which the desiredselectivityr-.in.accordance with the presenti inventionglis .attained.

"Example III .Zlihisexample is,given.:toi1lustrate the. eifectiof.ilariations. in .the totallamountiof HCl used zdurting the.chloridizing. reaction. In alltestsin this ,examplelfied Aroostook .oreoftheficomposition given-above and havingagrain size .of' minus. 150rme'sh .was. usedinv the same rotary furnaceand generallytunder theconditions described. Ex- Sample I. man tests sunder this example, gas,.was,.-passecl. through the furnace :at .the rate-of 10 cc: ofHz and50;cc=.of: HCLboth per minute; and .in.,-all.-tests, .the solidmaterial-was heldat 600 .F. iThetimeof the reactionswas varied in theseaseweralptests, t-soxas to subject. the solid: material.tQKdifieringVtotaL. amounts of HCl.

:A. In this 3. test the .:stoichiometric amount of .HCl requiredtoaconvert. all the manganese pres- ..entmto.Mn12 -washused. This: tookplace in 147 minutes. The -..resulting solid 'material, upon analysis,showed that 50.7 of the manganese presentphad been-converted to -MnClzand 3.5% sofuthe iron.present= had been converted to FeClz, g-ivingiaratio :of manganese to iron in the soluble ,prod-uct of. 6.10; 1.

B. this test 31109;, of the stoichiometric amount of Hcliwas passedthrough-"the fiurnace during a period of i62 minutes. .Therresifithigproduct showed, upon analysis that 55.9%:offthe manganese present hadbeen converted tozMnGlz, while 8.2 "of' the iron presenti' had'cbeenwon- 5 verted to FeClz, giving a: ratiooimanganese zto .iron in-thesoluble product of 2.66:1.

C. Inthisitest 150% of Jtherstoichiometiic amount of HCl was used duringa test peridd of 220::minutes. .The final:.product,' upon analysis,

been. converted to. MnClz and 10.2 ofiithedrnn present. had beenconverted to neon; giving. a 1: ratio softmanganesexto 'ironrimthe?solubleeportion of the final :productxof. 2i3'l 1.

Example IV This example "is merely to bring ouva comparison of "prior'tests, "illustrating" varying "gas compositions (as to 1-101)ancl'in'cludes wtestin which there wasa" low HCl concentration 'irrthegas present (see Example II--A) "whereinpnly 100 cc; of'I-ICl waspresentin'ajtotahofififificc or 6.13%. On the-other hand," in -Example 'III,'-substantially-83.3%"of the total'gas'present was no1.

There is furthef-illustrat ed the eff ect of diluent gas in ExampleII-'-A, --wherein nitrogen =-represented about 93% of the total gaspresent.

Whi-1e there is herein-disclosed in=siibstantial detail allthe-essentiahelements-of the: present *process and the ranges of-=equivalents where equivalents are'reasonably 'contempla-ted, it'-isintended that the presentinvention sh'a-ll'be considered to" includesuch reasonable equivalents as'will occur tothose' skilled'infthe artfrom= the foregoing disclosure.

"What is claimed is:

1. The process of selectively chloridi'zing manganese in the treatment-(immaterial-"containing 49 iron and manganese and in which the amount'of' iron present 'is substantially greater thanthe "amount of manganesepresent; comp'risingthe steps of introducing said-'ma-terialintoreaction :zone, -maintaining said material =in= said -zoneair-atemperature in the range of-about300 F. to about 900 F.,'passingHCl into'saidzone to contact said material= therein,-' supplyingto saidzone 1 an -'-amount of hydrogenwuflicientso that the gasesleaving-saidzzone contain at least 50 a trace of hydrogen, carrying onthe steps aforesaid untih at least about 50 "ofthemanganese present hasbeen" converted to -Mn'Cl2,"arid :dis-

continuing the processsteps aforesaidwhenthe ratio of "manganesechloride to ferrous chloride produced is at least 1: 1.

2."The process in accordance with "claim 1, 'wherein the- HClconcentrationin saidgases'is: at least about-6% by volume.

"3. -The process in accordance with claim :1, wherein said material ismaintained in' said" zone at a temperature in therange ofabout400-'F3-to abOut SOO 'F.

4. The process in "accordance with "claim 1, :wherein said mater-iaL isI a "naturally occurring -ore, selected from "the group consisting "oftGeorgia ochre, and F Red and Blue -Aroo'stook :ores.

5. L'I'hexprocess of selectivelychlori'c lizing managanese inthe'treatment of material containing 1 0 .rironiandi manganese and inwhich the amount of iron present is substantially greaterthan' theamount :of manganese :present, 'comprisingthe rstepssof introducingsaiclmaterial into-areaction ":zone, maintaining=r said material Linsaictzone at 7 5 1a temperatureijn r the range of about 300 F$ to showedthat 61.5%: of themanganesepresenthadabout 900 F1, passing HCl into saidzone to contact said material therein, supplying to said zone an amountof hydrogen suflicient so that the gases leaving said zone contain atleast a trace of hydrogen, and discontinuing the process aforesaid whenthe conversion of iron to ferrous chloride tends to give a final productwherein the ratio of ferrous chloride to manganese chloride is greaterthan about 1 :4.

6. The process of selectively chloridizing manganese in the treatment ofmaterial containing iron and manganese and in which the amount of ironpresent is substantially greater than the amount of manganese present,comprising the steps of introducing said material into a reaction zone,maintaining said material in said zone at a temperature in the range ofabout 300 F. to about 900 F., passing HCl into said zone to contact saidmaterial therein until the amount of HCl passed through said zone issubstantially that amount required to convert all the manganese presentin said material to MnClz, supplying to said zone an amount of hydrogensufficient so that the gases leaving said zone contain at least a traceof hydrogen, and discontinuing the process steps aforesaid when theratio of manganese chloride to ferrous chloride produced is at least1:1.

7. The process according to claim 6, wherein said process is carried onwith said material in said reaction zone at a temperature in the rangeof about 400 F. to about 800 F., and wherein said process isdiscontinued when the conversion of iron to FeClz tends to produce moreFeClz in respect to the MnClz produced than about 1:4 by weight.

IRVING P. WHITEHOUSE.

MARION ERNEST GRAHAM.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 2,290,843 Kinney July 21, 1942 2,425,995 Christensen Aug. 19,1947

1. THE PROCESS OF SELECTIVELY CHLORIDIZING MANGANESE IN THE TREATMENT OFMATERIAL CONTAINING IRON AND MANGANESE AND IN WHICH THE AMOUNT OF IRONPRESENT IS SUBSTANTIALLY GREATER THAN THE AMOUNT OF MANGANESE PRESENT,COMPRISING THE STEPS OF INTRODUCING SAID MATERIAL INTO A REACTION ZONE,MAINTAINING SAID MATERIAL IN SAID ZONE AT A TEMPERATURE IN THE RANGE OFABOUT 300* F. TO ABOUT 900* F., PASSING HCL INTO SAID ZONE TO CONTACTSAID MATERIAL THEREIN, SUPPLYING TO SAID ZONE AN AMOUNT OF HYDROGENSUFFICIENT SO THAT THE GASES LEAVING SAID ZONE CONTAIN AT LEAST A TRACEOF HYDROGEN, CARRYING ON THE STEPS AFORESAID UNTIL AT LEAST ABOUT 50% OFTHE MANGANESE PRESENT HAS BEEN CONVERTED TO MNCL2, AND DISCONTINUING THEPROCESS STEPS AFORESAID WHEN THE RATIO OF MANGANESE CHLORIDE TO FERROUSCHLORIDE PRODUCED IS AT LEAST 1:1.